ES2301141T3 - FORGING METHOD - Google Patents

Abstract

The invention is concerned with a method of forging a part of a predetermined shape from a workpiece comprising the steps of: radially closing opposed forging dies such that the forging dies move radially inward in a predetermined direction to contact the workpiece wherein the opposed forging dies define a cavity therebetween of the predetermined shape of the resulting part; applying axial and radial force to the workpiece with the radially closing forging dies, said applying step including the step of generating compressive and shear stresses within the workpiece such that the workpiece deforms outwardly to the predetermined shape defined by the opposed forging dies; and structurally reinforcing the opposed forging dies during the application of compressive and shear forces with a die housing which receives and circumferentially encompasses the opposed forging dies during the forging process.

Description

Forging method

The present invention relates to a method of forging to form metal parts, such as drilling tips Shovel type.

The drill-type drilling tips, Hereinafter referred to as "blade tips", they are used commonly for drilling or boring wood or other materials. A blade tip is typically used to drill holes that have a relatively large diameter from which a large amount of wood or other material. For example, during construction of a house, shovel tips are usually used to drill a series of holes, aligned, adjacent, to through which studs, conduits or wiring pass.

As shown in Figure 1, a tip of Conventional blade (1) includes an elongated body (2) defining a longitudinal axis (3). A blade part (4) is attached to a front end of the body and the rear end of the body, opposite the front end, it is received and held by a drill during drilling operations. The blade part is generally flat and, as shown in figure 2, define a center line (5) in the plane of the blade part and is extends through the longitudinal axis. The blade part it also includes a pair of lateral segments (4) that extend laterally in opposite directions. See, for example, the patent USES. No. 2,782,824 in the name of Robinson, issued on 26 February 1957; U.S.A. number 4,682,917 in the name of Williams, III, issued July 28, 1987; U.S.A. No. 4,950,111 in the name of Thomas, issued on August 21, 1990; U.S.A. No. 5,061,127 in the name of Thomas, issued on October 29, 1991; U.S.A. number 5,286,143 in the name of Schimke, issued on February 15, 1994; Y British patent number GB-2,130,935-A, published on 13 June 1984. A conventional blade tip also includes, of general mode, a generally triangular heel (7) attached to a front end of the blade part and extending axially from it in order to be coplanar with it. As is known to those skilled in the art, the heel serves to guide and center the blade tip during the operations of boring.

The heel (7), as well as each side segment (6), generally includes a cutting edge (8) to remove wood or other material when the blade tip (2) is rotated in a default rotation direction during the operations of boring. In particular, the heel cutting edges extend along opposite sides of the base thereof, at the end front of the blade part, to the front of the heel, that is, the heel point. In addition, the cutting edge of each side segment is formed at the front end of the blade part so that the cutting edge of the segment side will be attached to the workpiece when the blade tip rotate in the predetermined direction of rotation.

In operation, the heel cutting edges (7) initially drill a front hole in the part a to work. After that, the cutting edges of the segments sides (6) are coupled to the material and remove it from the piece to work to drill a hole of a predetermined diameter. Since the heel (7) of a conventional blade tip (2) is typically coplanar with the lateral segments usually planes, as shown in figure 2, each cutting edge of the generally triangular heel is adjacent to the cutting edge of the adjacent side segment. In this way, a pair of continuous cutting edges (8), each including an edge of Triangular heel cut and the cutting edge of the lateral segment adjacent. See, for example, U.S.A. number 2,782,624 to Robinson's name; U.S.A. number 4,682,917 in the name of Williams, III; U.S.A. number 5,221,166 in the name of Bothum, issued on June 22, 1993; U.S.A. number 5,286,143 in the name of Schimke; and U.S.A. number 5,291,806 on behalf of Bothum, issued on March 8, 1994.

Chip fragments created during drilling operations are generally conducted radially  along the cutting surface and towards the outer periphery of the hole that is being formed, due to the orientation of the cutting edges and to the rotation of the blade tip.

However, chip fragments cannot be removed so easily in the vicinity of the formed corner by the intersection of a heel cutting edge and the edge of cutting of an adjacent lateral segment. Rather, the chips are accumulate in the corner formed by the heel and the cutting edges of adjacent side segments, since chips are not directed away from the corner by the cutting edges that They cross Due to the accumulation of chip fragments, the edge of cut in the vicinity of the corner defined by the heel and the cutting edges of adjacent side segments do not cut Easily work the piece or remove material from it. In change, power or an additional torque must be applied to rotate the blade tip and to drill a hole through the piece to work once fragments of chip in the corner between the heel and the cutting edges of the adjacent side segments.

An additional problem caused by the movement radially out of the chip fragments along the surfaces of the cutting edges of the lateral segments is that chip fragments are made to enter the wall peripheral of the hole that is being formed, and they remain joined by this way between the peripheral wall and the outer edge of the rotating blade part. This union increases consumption more Electric drill bit.

The main cause of these problems, such as shown in figure 2, is that the cutting edges (8) of each side segment (6) are not aligned with the center line (5) that passes through the longitudinal axis (3). Instead, each edge of cut is located ahead of the center line in the direction predetermined rotation of the blade tip (1). Since the cutting edges are located in front of the center line, the chip fragments are not directed exclusively circumferential away from the cutting edges. Rather, the rotation of the blade tip also imparts a radial force component to the chip fragments that pushes them against the wall peripheral

During drilling operations, the tips of conventional shovel can also splinter the workpiece in which the hole is drilled. In particular, the blade tips conventional can splinter the workpiece at the points of entrance and exit and can produce a hole that has walls relatively rough sides, thus reducing the quality and cleanliness of the resulting hole. In many cases, clean holes of a relatively high quality are more desirable than holes that have rough side walls and splintered For example, you can drag by traction more easily wired through clean holes that have uniform side walls, since the holes that have rough and splintered side walls increase the resistance of friction on the cable being pulled by traction to through them and in some cases, they can cut or damage from otherwise the insulation surrounding the cable being dragged by traction through the holes.

Shovel tips are typically formed by A hot forging process. According to this process, it is cut in segments a coil of starting wire of a given diameter, each of them being approximately the length of a single blade tip. Each segment is then highlighted to form a part of material with an increased diameter in the first end of the segment, that is, a bulge of material that has a diameter increased by a smaller length in the first extreme. After that, the segment is heated and forged by compress the heated bulge of material between a couple of opposite matrices. Typically, the pair of opposite matrices will be they close rectilinearly, so that the bulging heated of material is subjected to compression forces that push the material until the predetermined form defined by the matrices The forged part can then be deburred and finished to produce blade tips, such as those described previously. It can also be stamped, during its manufacture, an identification mark on the blade tip. When cutting initially the starting wire, however, the pieces are they must manipulate and treat individually throughout the entire process of hot forging. For example, each individual piece is due properly align during each stage of the process to ensure that the blade tips formed in this way are within tolerance.

Regardless of the process by which you are formed, the behavior of a shovel tip is typically measured by several parameters. One of these parameters is the quality of the hole produced by a blade tip, as defined by the cleaning, including cleaning of entry points and output and the relative uniformity of the side walls of the resulting hole. In addition, the behavior of a shovel tip it is measured by the speed at which a hole of a diameter is cut default, as well as the power or torque required to cut the hole of the predetermined diameter. Finally it is also a parameter the long life or useful life of the tip itself Shovel, typically measured by hours of use or service. For the therefore, it is desirable to develop long-lasting blade tips that quickly drill high quality holes, while require a minimum amount of power or torque.

The U.S.A. No. 4,996,863 describes a forging method according to the preamble of claim 1.

In view of the previous background, a objective of the present invention is therefore to make known an improved method and apparatus for manufacturing a series of parts metal, such as blade tips, which reduce significantly the required handling and processing of the individual pieces.

This objective is achieved, according to the present invention, by a method comprising the characteristics of the claim 1.

According to the present invention, the matrices of Opposite forges are closed radially after insertion, such as by a driving device, in an internal cavity defined by a wraparound body of the matrices. The enveloping body of the matrices in which the matrices of circumferentially are inserted forging structurally comprises and reinforces the pair of matrices of forging during the forging process. Forging dies, typically a pair of forging dies, move according to this radially inward in a predetermined direction, oblique with respect to the respective contact planes defined by opposite contact surfaces. Contact surfaces respective impart, therefore, axial and radial forces to the less to parts of the piece to work to form the piece with the default within the cavity defined between the pair of opposite forging dies. Due to the shape of the surfaces of contact and orientation resulting from axial forces and applied radials, favorably oriented efforts are generated within the work piece that facilitate efficient training of the piece with the default form.

To maintain the default alignment of forging dies, the forging apparatus preferably includes a lateral matrix located adjacent to each of the surfaces opposite sides defined by the forging dies. According to this embodiment, the forging dies and the pair of side dies define a set of conical matrices that is received by the internal conical cavity defined by the enveloping body of the matrices Opposite forging matrices can also define entry and exit holes through which a Continuous metal material to forge a series of pieces.

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The forging method uses this way simultaneous axial and radial forces to deform a piece to to work. According to this, thin pieces that have a relatively large diameter can be easily forged according this aspect of the present invention. In addition, the required power to forge pieces of a predetermined size and shape are reduces compared to compression forging processes conventional by imparting forces in desirable positions within of the workpiece, as the forging dies are rotated within the enveloping body of the matrices.

Brief description of the drawings

Figure 1 is a front elevation view of a conventional drill-type drill tip.

Figure 2 is a view from one end of the conventional blade-type drilling tip of figure 1 during a drilling operation.

Figure 3 is a front elevation view of the drilling tip type shovel.

Figure 4 is a side elevational view of a drilling tip of shovel type.

Figure 5 is a view from one end of the blade type drilling tip of figure 3 when viewed according to line 5-5 of said figure 3, which is at length of the central longitudinal axis and showing the alignment of the front cutting edges of the side segments along of a central line that passes through the longitudinal axis central.

Figure 5A is a partial side view of a part of a side segment of the blade-type drilling tip of figure 5, which shows the angle of incidence and according to the line 5A-5A of said figure.

Figure 6 is a partial view, in section transverse, of a part of the heel of the drilling tip of shovel type of figure 3 showing the cutting edge of the heel, and according to line 6-6 of said figure.

Figure 7 is a partial view, in perspective, of a side segment of a drilling tip of shovel type that shows the corner chamfer part.

Figure 7A is a partial view, in section transverse, of a part of the lateral segment of the tip of shovel type drilling showing the angle of incidence of chamfer defined by the corner chamfer part and according to the line 7A-7A of said figure.

Figure 8 is a partial elevation view frontal, much larger scale of the blade part of a tip of drilling of shovel type.

Figure 9 is a view from one end, in cross section, of the blade part of the tip of shovel type drilling of figure 8 during an operation of drilling, which shows its distinct cross section in the form of Z and according to line 9-9 of said figure.

Figure 10, according to the line 10-10 of Figure 9, is a side view, in cross section, of a part of a side segment of the drilling tip type shovel during drilling operations to show the resulting chip removal.

Figure 11 is a front elevation view of an embodiment of a shovel-type drilling tip, in which the elongated shaft and the part of the thread are interlocked knife.

Figure 12 is a side view, in section transverse, of the realization of the type drilling tip blade of figure 11, showing the threaded shaft connection elongated to the blade part and according to the line 12-12 of said figure.

Figure 13 is a view from one end, in cross section, of the embodiment of the drilling tip of shovel type of figure 11, according to line 13-13 of said figure and showing the rotation of the blade part.

Figure 14 is a partial side view, in cross section, of a part of a side segment of the blade part of the realization of the type drilling tip blade of figure 11, showing an insert of the blades of section and according to line 14-14 of figure 13.

Figure 15 is a perspective view of a realization of automatic feeding of the drilling tip of shovel type that includes a threaded heel.

Figure 16 is a view with the pieces disassembled from the component parts of the embodiment of automatic feeding of the drilling tip of the shovel type of the figure 15.

Figure 17 is a block diagram of a hot forging process to manufacture the drilling tips Shovel type.

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Figure 18 is a block diagram representative of a forging process, by way of example, of the present invention to manufacture a series of parts, such as the shovel-type drilling tip of the present invention, from of a continuous metallic material.

Figure 19 is a schematic representation of an embodiment of the set of matrices to apply forces of compression during a forging operation.

Figure 20 is a schematic representation of the set of matrices and of an enveloping body of the matrices associated to apply axial and radial forces which, in turn, generate compression, tensile and shear stresses inside the workpiece during a forging operation.

Figure 21 is a schematic representation of a view from one end of a set of matrices and of a associated matrix envelope body to apply forces of compression and shear during a forging operation.

The present invention will be described in continuation more completely with reference to the accompanying drawings, in which an embodiment is shown Preferred of the invention. This invention can be realized, not However, in many different ways and should not be interpreted as limited to the embodiments set forth herein; plus well, this embodiment is disclosed so that this description be thorough and complete, and fully express the scope of the invention for those skilled in the art. Similar numbers They refer to similar elements throughout the patent.

As shown in Figures 3 and 4, a blade type drilling tip (10) of the present invention, hereinafter referred to as a "shovel tip", includes a elongated body (12) defining a central longitudinal axis (14) a through it. The back (16) of the body is adapted to be received and held by a drill (not illustrated). By For example, the elongated body typically includes a part cylindrical front and a back (16) that is hexagonal in cross section to be received and held firmly by the chuck of a drill (not illustrated).

The blade tip (10) also includes a blade part (18) attached to an elongated front body end (12) and which is integrally formed with the body (12) in the embodiment shown. The blade part includes a pair of generally flat lateral segments (20) that extend laterally in opposite directions from the central longitudinal axis (14). As shown in Figure 5, the lateral segments preferably define respective lateral planes (22) that are parallel to each other and to the central longitudinal axis. According to this embodiment, the blade part also includes a generally flat central segment (24) arranged along the central longitudinal axis and defining a central plane (26). More particularly, the central segment includes opposite sides (28) that are parallel to the central longitudinal axis, a rear end that is attached to the front end of the body and an opposite front end. According to this embodiment, the pair of lateral segments are attached to the central segment along the respective sides thereof. In particular, the pair of lateral segments are attached to the respective sides of the central segment, so that the lateral planes (22) defined by the respective lateral segments (20) cross the central plane (26) defined by the central segment (24 ) with an acute angle
(29).

The blade part (18) also includes a heel (30) attached to the front end of the blade part and which extends axially from it to center the blade tip (10) and to guide it during drilling operations. As best illustrated in Figures 3 and 8, the heel of this embodiment is generally triangular in shape and extends to a heel point on the central longitudinal axis (14). Heel also includes a pair of cutting edges (32) of the heel, shown in cross section in figure 6, which extend along from opposite sides of the heel between the heel point and a base of the heel at the front end of the blade part. The heel cut edges are located to establish contact initially with the workpiece during tip rotation shovel in the predetermined direction of rotation, as indicated by the arrows in the opposite direction to the needles of the clock in figure 5.

Each side segment (20) also includes a respective front cutting edge (34). Each cutting edge front is defined along the leading edge of the end front of the respective side segment to establish contact with the material and remove it initially as the blade tip (10) rotates in a predetermined direction of rotation during drilling operations. As shown by the arrows in figure 5, the blade tip is adapted to rotate in counterclockwise when viewed at length of the central longitudinal axis (14) from the front end towards the back end.

The respective front cutting edges (34) of the lateral segments (20) are preferably aligned each other along a central line (36) that passes through the central longitudinal axis (14) of the elongated shaft (12), as shown in figure 5. Being aligned along the line central that passes through the longitudinal axis central axis elongated, the front cutting edges remove material during drilling operations more efficiently than the tips of conventional shovel in which the front cutting edges of the respective side segments are not aligned with each other, but they are located, instead, in front of a central line passing through the central longitudinal axis (14). See for example, figure 2.

More specifically, the power or torque of forces supplied to the blade tip (10) of the present invention during drilling operations is transferred more efficiently, using the front cutting edges (34) aligned, to the piece to work. For a given tip size of shovel, the power supplied to the blade tip of the present invention is transferred more efficiently to the workpiece since the arm of the pair of forces of the blade tip is more short that the torque arm of a shovel tip conventional, as shown in Figures 1 and 2, due to the less in part, to the distinct Z-shaped cross section of the blade tip of the present invention. In addition, the power supplied to the blade tip of the present invention is also transfers more efficiently to the piece to work given that the total length of the cutting edges (32) of the heel and the front cutting edges of the blade tip of the present invention of a given diameter is less than the total length of the heel cutting edges and front cutting edges of a conventional blade tip of the same diameter. Due to the more efficient power transfer, the blade tip of the The present invention rotates faster, producing holes of a relatively high quality.

Alignment of the front cutting edges of the lateral segments (20) along a central line (36) passing through the central longitudinal axis (14) improves further shovel tip behavior when driving perpendicularly from the cutting edge and up the chip fragments removed, and not radially outward, as shown in the Figures 9 and 10. Pushing the chip fragments in the direction indicated, and not radially outward as they push the tips of conventional shovel, chip fragments do not hinder the subsequent rotation of the blade tip because the same between the blade tip and the side walls of the hole formed this way. According to this, the length is increased life of the blade tip by reducing wear on it and it improves the performance with which the blade tip drills a hole of a predetermined diameter.

As best illustrated in Figures 8 and 9, each cutting edge (32) of the heel preferably extends radially outward from at least one innermost part of the edge front cut (34) of the adjacent side segment (20). From this way, each heel cutting edge is radially separated of the leading cutting edge of the adjacent side segment. In addition, the heel (30) preferably defines a heel plane that it is oblique with respect to the corresponding lateral planes defined by the lateral segments, so that each edge of heel cut is offset angularly, also preferably, with respect to the leading cutting edge of the adjacent side segment in the direction of rotation default blade tip (10) when observed at length of the central longitudinal axis (14). In particular, each edge heel cut is positioned angularly backwards from the edge front cutting of the adjacent side segment in the direction Default rotation. In this way, each cutting edge of the heel is also angularly separated from the cutting edge front of the adjacent lateral segment. In addition, at least one part  of each cutting edge (32) of the heel extends axially towards behind the leading cutting edge (34) of the lateral segment adjacent in the longitudinal direction, so that each edge of heel cut is also axially separated from the cutting edge front of the adjacent lateral segment.

Due to the separation of each cutting edge (32) of the heel from the leading cutting edge (34) of the segment adjacent side (20), the drill-type drill tip (10) more efficiently removes material during the operations of boring. In particular, material is removed by a cutting edge of the heel or by a leading cutting edge of a lateral segment and is usually directed backwards from the cutting surface by the respective cutting edge. Due to edge separation heel cut from the front cut edge of the segment adjacent lateral, accumulate between the same few fragments of chip, if any, as described above along with Conventional shovel tips. Instead, the fragments of chip are usually directed backwards from the surface of cut so that the blade tip can continue to cut in the Workpiece with heel cutting edge and cutting edge adjacent front, improving performance in this way of the drilling operation.

Each side segment (20) may also include a corner chamfer part (35) respective. As it shown in figures 3 and 8, each corner chamfer part includes a chamfer edge that extends both axially towards back as laterally out from the cutting edge front (34) respective. In particular, the cutting edge front of each side segment typically extends laterally outward from an inner part to a part Exterior. According to this, the chamfer edge of each part of chamfer corner preferably extends both axially backward as laterally outward from the outside of the respective front cutting edge.

When extending both axially backwards and laterally outward from the leading cutting edge (34) respectively, the chamfer corner portions (35) can cut repeatedly the peripheral wall of the resulting hole as that the blade tip (10) of the present invention through the workpiece. Thus, The blade tip can efficiently produce high holes quality that have uniform peripheral walls and entry points and relatively clean exit.

As best shown in Figures 3 and 8, a chamfer angle (37) is defined between the chamfer edge of each respective chamfer corner part (35) and a line parallel to the central longitudinal axis (14). Typically, the angle chamfer is approximately between 30º and approximately 60 ° and, according to an advantageous embodiment, it is approximately 45º. As shown in Figure 8, each chamfer corner part also has a width (39) default measured along a collinear line with the edge front cutting (34) respective and extending between the edge of respective chamfer and a line parallel to the longitudinal axis central.

The default width of the parts of chamfer corner (35) typically varies directly with the shovel tip size (10), so that shovel tips older have corner chamfer parts with wider widths large and smaller shovel tips have corner chamfer parts With smaller widths. For example, for a shovel tip that It has a diameter between 3.81 cm (1.5 inches) and 2.22 cm (0.875 inches), the corner chamfer parts can have a width of about 0.23 cm (0.090 inches). Also for a blade tip that has a diameter between 2.06 cm (0.8125 inches) and 1.91 cm (0.75 inches), the corner parts of chamfer can have a width of approximately 0.18 cm (0.070 inches). Likewise, for a blade tip that has a diameter between 1.75 cm (0.6875 inches) and 1.59 cm (0.625 inches), the chamfer corner parts may have a width of approximately 0.15 cm (0.060 inches). Even more, a tip of shovel that has a diameter between 1.43 cm (0.5625 inches) and 1.27 cm (0.5 inch) can have corner chamfer parts with a width of approximately 0.13 cm (0.050 inches) while a blade tip with a diameter between approximately 1.11 cm (0.4375 inches) and 0.96 cm (0.375 inches) can have parts of chamfer corner with a width of approximately 0.06 cm (0.025 inches). However, the chamfer corner parts of the Shovel tips can have any number of widths.

As shown in Figure 5A, a part front of each side segment also defines preferably a cutting plane (38). The cutting plane crosses the lateral plane (22) defined by the respective lateral segment (20) to define among them an angle of incidence (40). Preferably the angle of incidence is between approximately 10º and approximately 20º and, more preferably, it is approximately 15 °. The edges of front cutouts (34) of the illustrated embodiment are arranged angularly ahead of the lateral planes of the segments respective sides in the predetermined direction of rotation of the blade tip (10) when viewed along the axis central longitudinal (14). As shown in figures 9 and 10, the chips removed from the workpiece by the edge of front cut are directed in this way upwards or towards back along the blade tip and away from the surface of cut by an additional rotation of the blade tip and partly by the angle of incidence defined between the cutting plane and the plane side.

In addition, each side segment (20) of the tip Shovel (10) may also include a front end having a front end surface (42) extending between the respective front cutting edge (34) and a rear edge (44). In one embodiment, each front end surface defines a respective front end plane that are cut with a plane (48) perpendicular to the central longitudinal axis (14) to define between yes a cut-out angle (50). Preferably, the angle of lip incidence is between approximately 10º and about 20 ° and, more preferably, is about 15th. Advantageously, the front end surface tilts backward from the leading cutting edge to the edge rear, so that only the leading cutting edge sets contact with the cutting surface during the operations of boring. In this way, drag forces are reduced or other friction forces generated between the blade tip rotary and workpiece and performance is further improved with the that drills the blade tip.

More particularly, in the embodiment shown in figure 6, each front end surface includes a first and second planes of the front end (46a) and (46b), respectively, that cut with a plane (48) perpendicular to the axis longitudinal center (14) to define each other a first and second angles of incidence (50a) and (50b) of lip, respectively. Such As shown, the second angle of lip incidence is, typically, greater than the first angle of lip incidence for further reduce drag forces or other friction forces generated between the tip of the rotating blade and the workpiece. By example, in one embodiment, the first and second angles of Lip incidence are approximately 5th and 8th, respectively. However, the first and second angles of lip incidence

As shown in Figures 7 and 7a, the chamfer corner part (35) of each side segment (20) includes a chamfer surface that extends between the edge of respective chamfer and a trailing edge. Each chamfer surface defines a chamfer plane that is cut with a perpendicular plane to the lateral plane (22), determined by the lateral segment respective, to define in this way an angle of incidence of chamfer (41). Advantageously, the chamfer surface tilts radially inward from the chamfer edge to the edge later to define a chamfer incidence angle between approximately 10 ° and approximately 20 ° and, in one embodiment preferred, it is approximately 12º.

Even more, each side segment (20) of the Illustrated embodiment of the blade tip (10) includes a first side attached to the central segment (24) along one of its sides (28), and an opposite second side (52) that defines a second outer surface or lateral surface. The second surface or outer side surface extends between the front edges and subsequent respective and as shown in figure 5, follow preferably the arc of a circle in lateral cross section to further reduce drag forces or other forces of friction generated by the rotation of the blade tip inside the orifice. Alternatively, the lateral surface can be tilted radially inward from the leading edge to the edge posterior, so that only the leading edge of the surface lateral segment lateral contact the walls side of the hole to further reduce the seizing the blade tip.

The second sides (52) of the segments respective sides (20) also preferably lean towards  inside in an axial direction from the front end to the rear end of the blade part (18). In this way, such as shown in figure 3, an inclination angle (53) of the lateral surface, typically, about half of 1º, or ½º, is defined between the plane of the lateral surface and a line parallel to the central longitudinal axis (14). By leaning towards within the second sides of the lateral segments, the lateral surfaces only contact, preferably, with the workpiece near the cutting surface, so that drag forces or other forces of friction.

The blade tip (10) of the present invention It can be manufactured integrally from a single piece of metal, as shown in figures 3 and 4. Alternatively, The blade tip can be formed from the combination of Various components For example, as shown in the figures 11 and 12, the elongated body (12) and the blade part (18) can be formed separately and subsequently joined to form the shovel tip

In particular, the blade part (18) can include an internal cavity (54) that opens at one end posterior, to which the elongated shaft (12) is attached. Correspondingly, the elongated shaft (12) may include a element that extends forward (56) adapted to be received within the internal cavity defined by the part of knife.

The blade tip (10) of this embodiment also includes means for locking the element that extends forward of the body into the internal cavity of the blade part. For example, the interlocking means may include complementary threaded parts defined within the internal cavity of the blade part and along the element that extends forward of the body, so that the body and the blade part can be connect threadedly. As is known to those skilled in the art, the threaded connection is preferably self-tightening, so that the rotation of the blade tip in the predetermined direction of rotation further tightens the threaded connection between the body and the blade part. The blade tip may also include other locking means. For example, the blade part and the body can be snapped or joined, such as by strong welding, to form a firm interconnection between them. In addition, the body can include the internal cavity
and the blade part may include a corresponding element that extends backward to interlock the pieces.

As shown in Figures 13 and 14, each lateral segment (20) of an embodiment of the blade tip (10) It may include an insert (58) of the cutting blades. Every insert of the cutting blades is typically constituted by a relatively hard material, such as carbide, and is mounted to along the front end of a respective side segment to define the respective front cutting edges (34) and in some embodiments, the respective chamfer edge (35). Further, the front cutting edges defined by the inserts of the respective cutting blades of this embodiment may be aligned along the center line (36) that passes through the central longitudinal axis (14) of the elongated body (12), as described above

Although a blade tip (10) may be consisting of multiple pieces and can also include inserts (58) of the cutting blades as shown in the figures 11-14, a blade tip of the present invention It can consist of multiple pieces, not including inserts of the cutting blades. Similarly, a shovel tip can be manufactured as an integral unit, but can continue including inserts (58) of the cutting blades. Alternatively, the front cutting edges (34) and in some embodiments, the chamfer edges (35) of a blade tip the present invention can be formed by depositing a layer of a relatively hard material, such as diamond, on a substrate, namely, the leading edge of the leading end of each segment lateral (20). The relatively hard material is preferably more resistant than the side segments that are below.

As shown in Figure 15, the tip of shovel can also be automatic feed to facilitate the entry and advance of the blade tip through a piece to to work. According to this embodiment, the blade part (18 ') of the blade tip (10 ') includes a threaded heel (30') attached to the end front of the blade part and extends axially from the same. As shown, the blade part of the embodiment Automatic blade tip feed also includes a pair of lateral segments (20 ') generally flat that extend laterally in opposite directions from the axis central longitudinal (14 ') of the blade tip. In the realization shown, the side segments include corner parts of respective chamfer (35 ') and front cutting edges (34) respective that are aligned with each other along a line center (36 ') that passes through the central longitudinal axis. From this way, among the characteristics that the realization of automatic feeding of the blade tip has in common with the other embodiments described above is the section Z-shaped cross section of the blade part, as best illustrated in figures 5, 13 and 15, and the corner parts of chamfer of the lateral segments, as best shown in Figures 3, 8 and 15. According to this, the realization of automatic feeding of the blade tip shown in the figure 15 also provides the numerous performance improvements of drilling described in detail above.

The automatic feeding of the blade tip (10 ') can be manufactured according to any method, such as hot forging, known to those skilled in the art. Alternatively, performing automatic feeding of the blade tip can be formed according to the forging process described to continuation. As shown in Figure 16, however, another method to form the realization of automatic feeding of the blade tip is to join several pieces to form the tip of blade of figure 15. In particular, the threaded heel (30 ') is shape at a first end of a body (12 ') elongated by any conventional technique The rest of the blade part, including the lateral segments (20 ') that extend in opposition, are shape as a separate piece that includes a threaded hole internally that extends axially through it. He rest of the blade part is mounted on the elongated body and is threaded coupling to the threaded heel. After that, a tubular sleeve (57 ') can be placed on the elongated body and can be stamped on it to firmly fix the part of blade to the body and to form the feeding realization automatic blade tip shown in figure 15.

The blade tip (10), and its parts individual, can be formed from a forging process in hot as illustrated schematically in figure 17. Such as shown, a continuous length of metallic material (59), for example wire, it is initially cut into a series of pieces, each of which will eventually form a shovel tip. After that, the individual pieces are highlighted to form a bulge of material at a first end of the piece (62). Each highlighted piece is heated and then forged sequentially, as shown by blocks (64) and (66), respectively. For a workpiece consisting of steel alloy, for example, each highlighted piece is heated to a temperature between 650ºC (1,200ºF) and 1,200ºC (2,200ºF). After this, a pair of opposite matrices (68) can be closed around The heated piece. Opposite matrices define a cavity of a default form that, in turn, defines the resulting form of the forged piece. Once forged, the opposite matrices will be can be opened and excess material ("flash") can be cut of the forged part, as shown in the block (70). After of this, an identification mark, such as the width of the blade part, can be stamped on the piece before treating thermally, finish and pack the blade tip, as shown in blocks (72), (74), (76) and (78), respectively.

Alternatively, the blade tip (10) can be form by a forging method as shown in figure 18. Although it is mainly described below as a method of cold forging, the workpiece can be heated before the forging stage, so that the forging method is a method of warm or hot forging. The temperature ranges at that each of the various materials should be heated from of which the workpiece can be formed to be forged in cold, warm or hot depend, among other things, on the strength and internal properties of the respective material, and They are known to those skilled in the art. For example, the work pieces made of alloy steels have, typically, a temperature between room temperature and 150 ° C (300ºF) during cold forging operations, a temperature between 100ºC (200ºF) and 760ºC (1,400ºF) during the operations of warm forging, and a temperature between 650ºC (1,200ºF) and 1,200ºC (2,200ºF) during hot forging operations. In addition, the forging method of the present invention, which includes a step of hot forging of a work piece is particularly effective for forging work pieces made of a material which has a relatively low melting point, such as aluminum, bronze, zinc and copper.

In addition, although it is described along with the manufacture of a series of blade tips, the method of forging in cold shown in figure 18 can produce a wide variety of parts including, without limitation, screwdriver tips and router tips, and is suitable for manufacturing other parts metal, such as rotor shafts.

As shown in Figure 18, a series of pieces, such as the blade tip, are forged from a continuous length of metallic material (80), such as wire Continuous departure. Typically, the metallic material is consisting of alloy steel, however, the metallic material it can be constituted by any known forgeable material by those skilled in the art. For example, the metallic material It may consist of copper, aluminum, titanium, zinc, bronze or Alloys thereof.

Regardless of the material, the material continuous metal is initially straightened, for example by making pass the metallic material through a series of rollers aligned, as shown in block (82). The material straightened metal is then advanced incrementally, for example by means of an orientation device, as shown in the block (84). The guiding device advances longitudinally incrementally the metallic material continuous a predetermined linear distance in one direction towards down. As shown in block (86), a part is pressed front of the continuous metal material, typically by a clamp such as a pair of opposing clamping dies, to continuation of each incremental advance of the metallic material, of so that the front part of the metallic material is held in a fixed position

Each time the metallic material (80) is tightened and held in a fixed position, a part of the continuous metal material anterior to the front that is tight. As shown schematically in block (88) and It is described in more detail below along with the figures 19-21, the means for forging are typically a forging that includes a series of matrices (90) that are closed radially around the continuous metal material. The series of closed matrices define a cavity in a predetermined way which, in turn, defines the resulting form of the forged part of the metallic material In addition, the series of closed matrices define inlet and outlet openings through which the Continuous metal material during the forging stage.

As shown in block (85), the Metallic material (80) can be heated before the stage of forge to increase the malleability of it. For example, a induction coil can be arranged around the material Continuous metal prior to the series of matrices (90). Alternatively, the matrices may include elements of heating to heat the metallic material within the matrices, such as by induction heating, during forging stage. However, as described above, The method of the present invention also includes cold forging in that the metallic material is generally unheated or, for an alloy steel material, it has a temperature between the room temperature and 150ºC (300ºF), for example.

During the forging stage (88), the material Continuous metal (80) grows longitudinally. This growth longitudinal is compensated by a compensating device that allows longitudinal upward movement of that part of the continuous metallic material that is prior to the fixed position. In one embodiment, the series of forging dies (90) are mounted on a car (92) that is adapted to move longitudinally. In this way, the longitudinal growth of the continuous metallic material between the forged part around the the matrix series and the front part are closed radially that is tight makes the car move in the direction longitudinal up. In this way, the array series is they keep closed around the same part of the material metallic during each stage of forging, while allowing the longitudinal upward movement of the continuous metal material and, in some embodiments, the corresponding rotation of the coil on which the metal material supply is mounted, to compensate for the longitudinal growth of the metallic material. As shown in Figure 18, the car may be deflected longitudinally, such as by a spring or other means antagonists (94), to prevent excessive movement in the direction up and to return the car to its position Initial after each stage of forging.

After forging a part of the material metallic (80), the series of matrices (90) open radially and the front part of the metallic material is released by the matrices of press on (86), so that the guiding device (84) can Advance the continuous metal material incrementally. After that, the tightening and forging stages are repeated preferably to forge another piece from the material continuous metal As shown in block (86), the tightening dies also preferably mark a mark of identification on a previously forged piece. In addition, you can deburring a piece previously forged to the shape predetermined of it removing the burrs or the material in excess generated during the forging of the piece, as shown in the block (87), while the metal material is pressed and He is forging another piece.

As shown in block (96), only cut the piece, such as by cutting means, from the part of the continuous metallic material (80) that extends beyond the tight front of the metal material after stages of forging and stamping. Once separated, the pieces Individuals can be heat treated, finished and packed, as shown in blocks (98), (100) and (102), respectively.

When treating the series of parts while they are still joined by the continuous metallic material, it is reduced significantly the degree of handling and transport of individual pieces. In addition, the alignment of the matrices (90) of The forging means with respect to the metallic material can be maintained more precisely to produce high quality parts that have clearly defined characteristics, such as, for example, the radial, angular and longitudinal separation described above of the cutting edge (32) of the heel from the front cutting edge (34) of the respective lateral segments (20) of part (18) of blade tip blade (10). In addition, by altering the distance of the longitudinal feed provided by the guiding device, pieces of varying lengths can be produced from same continuous metal material, such as blade tips that They have an elongated body of variable length.

As shown in Figures 19-21, a piece with a predetermined shape can be forged from a workpiece (120) according to the forging method of the present invention. According to the present invention, a series of pieces, such as blade tips, can be forged from a continuous metal material as described above or, alternatively, one or more individual pieces can be forged. In addition, the forging method of the present invention can also produce a wide variety of other parts, such as screwdriver bits and router bits, and is considered to be suitable for manufacturing other metal parts, such as rotor shafts and parts. chamfer corner of the side segments, as best shown in figures 3, 8 and
fifteen.

In addition, although the blade tip (10) could be forge to have a blade part (18) that includes segments opposite sides (20) on either side with corner parts of respective chamfer (35), the side segments of the tip of Shovel of the present invention are typically polished, such as by a conventional polishing process, which follows the process of forging, to form the respective corner chamfer parts. From according to this, the corner chamfer parts that define a chamfer angle (37) predetermined with respect to a line parallel to the central longitudinal axis (14) can be polished with precision in the respective lateral segments.

As shown in Figure 19, the apparatus forging (110 ') includes opposite forging dies (112), typically a pair of opposing forging matrices, which define a cavity (114) between them. The cavity, in turn, defines the resulting form of the piece formed by the method and apparatus of forging. More specifically, at least one forge matrix, and preferably each of them, may include a surface of contact (116) of a Z-shaped configuration that defines A part of the cavity. According to one embodiment, the matrices of Opposite forges include two opposing sets of forge dies, each of which includes at least one forging matrix that it has a contact surface of a configuration in the form like of Z.

As described above along with the blade tip, the Z-shaped cavity includes a part central (134) defining a central plane (136) and parts opposite sides (138) extending from opposite sides from the central part. Opposite side parts define planes corresponding laterals (140) that are oblique with respect to the plane central. The respective contact surfaces establish contact with the piece to work (120) and make up the same with the shape Default of the resulting piece. Each contact surface (116) respectively also preferably includes at least a part which is relatively flat and defines a contact plane (118) that It is parallel to the relatively flat part of the other matrix.

The forging apparatus (110) also includes means to radially close the opposing forging dies. As it described below with respect to figures 20 and 21, the means for radially closing the forging dies include a enveloping body (130) of the matrices. In particular, the matrices forging (112) move radially inward in one direction default, as shown by the arrows in the figure 19, after the relative movement between the enveloping body of the matrices and the pair of opposing forging dies, as shown in figure 20 and described below with detail.

Various parts of the contact surface (116) respectively can define a contact plane (118) of a wrought iron matrix (112). For example, as shown in the figure 19, the central parts (117) of the contact surfaces respective are oblique with respect to the default address in the one that closes the forging dies and defines contact planes respective. In this way, the contact plans impart axial and radial forces (142) and (144), respectively, to the piece to work which, in turn, result in efforts of compression, traction and shear inside the part a Work during the deformation process. The components resulting from compression and shear forces deform therefore out the workpiece (120) with the shape default defined by the forge matrices.

More particularly, an angle (122) is defined between the respective contact planes (118) and a plane reference (124) perpendicular to the default address in the one moving the forging dies (112), as shown in Figure 19. In a preferred embodiment, the angle is between about 5th and about 15th and, in one example specific, it is approximately 10º. As used in the present memory, the expression "compression force" includes those forces in the predetermined direction in which the forging dies, and the expression "shear force" includes those lateral forces that tend to deform radially out the workpiece (120). In this way, for a given amount of input power, the magnitude of the force of shear and compression force imparted to the part a work increases and decreases, respectively, as it increases the defined angle between a respective contact plane and the plane reference. In this way, for a given amount of power of input, the magnitude of the shear force and the force of compression imparted to the workpiece decreases and increases, respectively, as the defined angle between a respective contact plane and reference plane.

At least the parts of the workpiece (120) that are subjected to shear force and, consequently, to shear stress, deform more easily, since the shear strength of the most common work pieces, is say, most metal materials, is less than the compressive strength of the same material. Typically, the shear strength of metallic materials is approximately 60% of the compressive strength thereof material. For example, during the formation of a shovel tip according to this method, both lateral segments are subjected preferably at relatively high shear stresses to produce the maximum lateral displacement with respect to a piece to work, or wire, of the minimum initial diameter.

In this way, it is significantly required less input power to deform a workpiece (120) with shear forces than with compression forces. Besides, the application of shear forces that deform more easily radially out a workpiece allows it to decrease the relationship between the thickness of a piece and the width or the diameter of it, so that the thin pieces that they have a relatively large diameter, such as a tip of shovel, can be easily forged according to the present invention.

However, the application of force of shear to deform the workpiece (120) increases significantly the forces that the forging dies and the Envelope body of the matrices must withstand during the process forging and, accordingly, have been avoided in the processes of conventional forging in which the forging dies are closed from rectilinear way to impart compression forces on the part to work. In order to withstand the increased forces, the opposite forging dies (112) are constituted, in a preferred embodiment, for a high speed steel and, more preferably, they are made of high speed steel CPM® REX? M4, or an equivalent, marketed by the firm Colt Industries Crucible Specialty Metals Division of Syracuse, New York, and described in more detail in a publication entitled "Crucible Data Sheet by Colt Industries Crucible Specialty Metals Division ", which bears a document number D88 308-5M-776.

In addition, the time required to deform a Workpiece (120) with shear forces is greater, so general, that the corresponding time required to deform a similar workpiece with compression forces. In this way, for parts that have a relatively small diameter, such as Shovel tips with a diameter of approximately 0.96 cm (3/8 of inch) or less, in which the deformation of the workpiece with shear forces it will not retain a significant amount input power, the angle (122) defined between the planes of contact (118) and the reference plane (124) are decreases, or is eliminated, so that quantities are imparted increasing compression force to the workpiece and the deformation process occurs more quickly. In these realizations, however, you can continue to impart forces of shear, although to a lesser extent, thanks to the surfaces of contact including oblique side parts, such as illustrated by the Z-shaped cavity of Figure 19. To parts with a relatively large diameter, such as tips shovel with a diameter of approximately 1.11 cm (7/16 inch) or major, in which the deformation of the piece to work with forces Shear will retain a significant amount of power from input, the respective contact planes are arranged preferably at an angle, such as 10 °, for example, with Regarding the reference plane.

The means to close the forging dies opposites preferably include means to maintain a default alignment of opposing forging dies (112) during the forging process. As shown in figures 19 and 21, the means to maintain the alignment of the matrices of opposite forges preferably include a pair of matrices opposite sides (126). Opposite side matrices are located adjacent to opposite side surfaces (128) defined by the opposing forging matrices. As shown schematically in figure 21, the opposite forging dies and the pair of lateral matrices define a set of matrices that It has a generally conical shape.

As also shown schematically in Figures 20 and 21, the means for closing the forging dies Opposites preferably include an enveloping body (130) of the matrices, including end plates (146), which define a conical cavity in it. The internal conical cavity defined by the enveloping body of the matrices is adapted to receive the set of conical matrices formed in a complementary manner, so that the enveloping body of the matrices comprises circumferentially the set of matrices. In this way, at axially insert the array set into the enclosure of the matrices, such as with a matrix press or a conical pressure device (not illustrated), forging dies opposite and the pair of lateral matrices are closed radially around the piece to work. The resistance of the set of matrices and their resulting ability to withstand forces generated during the deformation of the work piece with forces axial and compression (142) and (144) which, in turn, generate compression, tensile and shear stresses, is improved also by the radial direction in which the set of matrices and by the surrounding relationship of the enveloping body of the matrices to the set of matrices.

The enveloping body (130) of the matrices is constituted, also preferably, by a relatively material resistant, such as high speed steel and more preferably, high speed steel CPM® REX? M4. In addition, although the pressure or force required to insert the set of matrices in the envelope body of the matrices will vary depending on the treatment conditions, including the type of material from which the workpiece is formed and the size and shape of the resulting piece, a press Hydraulics, such as a 500 ton press, has produced Shovel tips made from 1050 carbon steel.

In addition, an embodiment of the matrix set from this aspect you can also define input and output holes (132), as shown in Figure 20, through which can extend a continuous metallic material so that it they can form a series of pieces, as described previously. However, the method of forging of the present invention can also be used to form individual pieces, without going beyond the scope of the invention.

In the drawings and in the specification, have disclosed preferred embodiments of the invention and, although they have used specific terms, they are used only in a generic and descriptive sense and not for limiting purposes, being exposed the scope of the invention in the following claims.

Claims (12)

1. Method for forging a piece with a shape default from one piece to work (59, 80), which It comprises the following stages: radially close opposite forging dies (112), so that the forging dies move radially in in a predetermined direction to set contact with the workpiece, in which the forging dies opposite define a cavity (114) between them with the shape default of the resulting piece (120), including each of said dies forging a contact surface (116) that defines  a part of the cavity to establish contact with the piece a work and conform it with the default form of the resulting piece, including each respective contact surface at least a relatively flat part that defines a plane of contact (118) that opposes and is parallel to a relatively part flat of the other matrix; apply axial and radial forces to the piece to work with radially closing forging dies, of so that the workpiece is deformed out to the shape default defined by the opposing forge matrices; Y Structurally reinforce the opposing forging dies with an enveloping body (130) of the dies that receive and circumferentially comprise the opposing forging dies during the forging process, characterized in that said predetermined direction is oblique with respect to the corresponding contact planes defined by the opposite contact surfaces, so that the respective contact surfaces impart axial and radial forces at least to parts of the workpiece to generate compression and shear forces within it, and because the method comprises structurally reinforcing the matrices of opposing forges during the application of said compression and shear forces. 2. Method for forging a piece with a predetermined shape, according to claim 1, characterized in that the step of radially closing the opposite forging dies includes a phase of maintaining a predetermined alignment of the same while the forging dies are closed radially. 3. Method for forging a piece with a predetermined shape, according to claim 2, characterized in that the phase of maintaining the predetermined alignment of the opposing forging dies includes the steps of: place a lateral matrix (126) adjacent to each one of the opposite lateral surfaces (128) defined by the opposite forging dies, so that the forging dies opposite and the pair of lateral matrices define a set of conical matrices; place the set of matrices in the body matrix envelope that defines a conical opening in the same to receive the set of conical matrices formed of complementary mode; and insert the array set into the enveloping body of the matrices so that the matrices of opposite forging and the pair of side dies close radially while maintaining the default alignment of the forging dies. 4. Forging method according to claim 3, characterized by the use of means for maintaining a predetermined alignment of the opposing forging dies while the forging dies are closed radially. 5. Forging method according to claim 4, characterized in that the opposite forging dies define opposite lateral surfaces, and wherein the means for maintaining the predetermined alignment of the forging dies include a pair of lateral dies (126) of which one is located adjacent to each lateral surface defined by opposing forging dies. 6. Forging method according to claim 5, characterized in that the opposite forging matrices and the pair of lateral matrices define a set of conical matrices, and the internal opening defined by the enveloping body of the matrices is conical to receive the set of Conical matrices formed in a complementary manner so that, when the set of matrices is inserted into the housing of the matrices, the opposite forging matrices and the pair of lateral matrices are closed radially. 7. Forging method, according to any of the preceding claims, characterized in that the contact plane of each respective forging matrix and a reference plane (124) perpendicular to the predetermined direction of movement of said opposite forging dies define one another angle (122) between approximately 5 ° and approximately 1 °. 8. Forging method according to any of the preceding claims, characterized in that the opposite forging dies define inlet and outlet holes through which a continuous metallic material (59, 80) extends so that a series can be forged of pieces with the default form. 9. Forging method according to any of the preceding claims, characterized in that the opposing forging dies are constituted by M4 high speed steel. 10. Forging method according to any of the preceding claims, characterized in that the casing body of the dies is constituted by M4 high speed steel. 11. Forging method, according to any of the preceding claims, for forging a piece that has a diameter of at least 11 mm (7/16 inch), at which an angle of approximately 10º is defined between each respective plane of contact and a plane perpendicular to the default address in the one that move the forging dies radially inwards opposite. 12. Forging method, according to any of the preceding claims, for forging a piece that has a diameter smaller than 11 mm (7/16 inch), in which each plane respective contact is parallel to a plane perpendicular to the predetermined direction in which they move radially towards inside the forging dies opposite.